The present invention relates to evaporators for use in air conditioners for motor vehicles.
Evaporators for use in motor vehicle air conditioners and the like are already known which comprise first and second header portions arranged in parallel, and flat tubular portions arranged in parallel and each connected at opposite ends thereof to the header portions, each of the header portions being provided with a partition for blocking a refrigerant flowing inside thereof and directing the refrigerant toward some of the flat tubular portions to thereby form a refrigerant channel comprising a first path, at least one intermediate path and a final path.
With the conventional evaporator described above, the number of paths, i.e., the number of blocking partitions, is altered to obtain optimally divided flows of the refrigerant. With decreases in the width of evaporators in recent years, however, the refrigerant passing apertures are reduced in area, and the refrigerant is moved from path to path at an increased rate, impairing the division of the refrigerant in a downstream path (especially in the final path) and permitting the refrigerant to unevenly pass through the flat tubular portions providing this path, with an increased amount of the refrigerant flowing through the flat tubular portion at the downstream extremity. This imposes a limitation on the improvement of the cooling ability.